CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Government contract	$ 0	$ 2,184	$ 33,344
Grant and other	31,176	13,169	2,906
Total revenue	31,176	15,353	36,250
Expenses:
Research and development	168,435	237,939	162,644
General and administrative	34,451	46,527	30,842
Total expenses	202,886	284,466	193,486
Loss from operations	(171,710)	(269,113)	(157,236)
Other income (expense):
Investment income	1,946	2,143	660
Interest expense	(14,072)	(12,965)	(241)
Other income (expense)	67	(31)	(120)
Net loss	$ (183,769)	$ (279,966)	$ (156,937)
Basic and diluted net loss per share	$ (0.63)	$ (1.03)	$ (0.6)
Basic and diluted weighted average number of common shares outstanding	292,669	270,802	262,248